The present invention relates to a device for marking and aligning positions on a heart for receiving a device for treating the heart. In particular, the device and a method of using the device are directed toward locating and marking positions on the heart and securing the device to the heart to guide placement of a device for reducing stress on the heart.
Heart failure is a common outcome in the progression of many forms of heart disease. Heart failure may be considered as the condition in which an abnormality of cardiac function is responsible for the inability of the heart to pump blood at a rate commensurate with the requirements of the metabolizing tissues, or can do so only at an abnormally elevated filling pressure. There are many specific disease processes that can lead to heart failure. Typically these processes result in dilatation of the left ventricular chamber. Etiologies that can lead to this form of failure include idiopathic, valvular, viral, and ischemic cardiomyopathies.
The process of ventricular dilatation is generally the result of chronic volume overload or specific damage to the myocardium. In a normal heart that is exposed to long term increased cardiac output requirements, for example, that of an athlete, there is an adaptive process of slight ventricular dilation and muscle myocyte hypertrophy. In this way, the heart fully compensates for the increased cardiac output requirements. With damage to the myocardium or chronic volume overload, however, there are increased requirements put on the contracting myocardium to such a level that this compensated state is never achieved and the heart continues to dilate.
One problem with a large dilated left ventricle is that there is a significant increase in wall tension and/or stress both during diastolic filling and during systolic contraction. In a normal heart, the adaptation of muscle hypertrophy (thickening) and ventricular dilatation maintain a fairly constant wall tension for systolic contraction. However, in a failing heart, the ongoing dilatation is greater than the hypertrophy and the result is a rising wall tension requirement for systolic contraction. This is felt to be an ongoing insult to the muscle myocyte resulting in further muscle damage. The increase in wall stress also occurs during diastolic filling. Additionally, because of the lack of cardiac output, a rise in ventricular filling pressure generally results from several physiologic mechanisms. Moreover, in diastole there is both a diameter increase and a pressure increase over normal, both contributing to higher wall stress levels. The increase in diastolic wall stress is felt to be the primary contributor to ongoing dilatation of the chamber.
Another form of heart failure results from the formation of one or more zones of ischemia, or infarction, of the myocardium. Infarction occurs when blood supply to the heart tissue has been obstructed resulting in a region of tissue that loses its ability to contract (referred to as infarcted tissue). The presence of infarcted tissue may lead to three conditions in the heart causing cardiac malfunction. These conditions are ventricular aneurysms (ventricular dyskinesia), non-aneurysmal ischemic or infarcted myocardium (ventricular akinesia), and mitral regurgitation.
A ventricular aneurysm is formed when the infarction weakens the heart wall to such an extent that the tissue stretches and thins, causing, for example, the left ventricular wall to expand during systole (dyskinesia) and form a bulge in the heart wall. Non-aneurysmal ischemic or infarcted myocardium (akinesia) occurs when a major coronary artery is occluded and results in infarction in the myocardial tissue, but without a bulging aneurysm. Finally, mitral regurgitation is a condition whereby blood leaks through the mitral valve due to an improper positioning of the valve structures that causes it not to close entirely. If the infarcted or aneurysmal region is located in the vicinity of the mitral valve, geometric abnormalities may cause the mitral valve to alter its normal position and dimension, and may lead to annular dilatation and the development of mitral regurgitation.
Prior treatments for heart failure associated with such dilatation fall into three general categories. The first treatment is pharmacological, for example, diuretics and ACE inhibitors. While drug therapies offer some beneficial effects, they do not stop progression of heart disease. The second treatment uses assist systems, for example, pumps. Although such mechanical assist devices may sustain the patient by performing the functions of the heart, such devices, at this point in time, are stop-gap measures at best, sustaining a patient until a transplant is available. Finally, surgical treatments also have been experimented with, including, for example, the Batista partial left ventriculectomy in which the left ventricle is surgically remodeled by removing a segment of the muscle wall. However, this is an extremely invasive procedure which reduces muscle mass of the heart.
The advantages and purpose of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages and purpose of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
One aspect of the present invention includes an alignment device. The alignment device includes a first arm supporting a first heart engaging member, the first heart engaging member having a heart contacting surface, a second arm supporting a second heart engaging member, the second heart engaging member having a heart contacting surface, and a handle assembly having a first handle portion and a second handle portion, wherein the first handle portion supports the first arm and the second handle portion supports the second arm, the first and second handle portions being releasably connected to permit movement independent of one another.
According to another aspect of the invention, an alignment device includes a first arm supporting a first heart engaging member, the first heart engaging member having a heart contacting surface, wherein the first heart engaging member articulates with respect to the first arm, a second arm supporting a second heart engaging member, the second heart engaging member having a heart contacting surface, wherein the second heart engaging member articulates with respect to the second arm, and a handle assembly connected to the first and second arms.
According to a further aspect of the invention, an alignment device is provided. The alignment device includes a first arm supporting a first heart engaging member, the first heart engaging member having a first heart contacting surface and defining at least one suction chamber, a second arm supporting a second heart engaging member, the second heart engaging member having a second heart contacting surface and defining at least one suction chamber, and a handle assembly connected to the first and second arms.
According to yet another aspect of the invention, an alignment device includes a first arm supporting a first heart engaging member, the first heart engaging member having a first heart contacting surface, wherein the first heart engaging member articulates with respect to the first arm and the first heart engaging member defines at least one suction chamber, a second arm supporting a second heart engaging member, the second heart engaging member having a second heart contacting surface, wherein the second heart engaging member articulates with respect to the second arm and the second heart engaging member defines at least one suction chamber, and a handle assembly having first and second handle portions, wherein the first handle portion supports the first arm and the second handle portion supports the second arm, the first and second handle portions being releasably connected to permit movement independent of one another.
According to another aspect of the invention, a method of implanting an elongate member transverse a heart is provided. The method includes selecting first and second locations on the heart, placing a first heart engaging member at the first location, placing a second heart engaging member at the second location while the second heart engaging member is not connected to the first heart engaging member, passing a path-creating member through the first and second heart engaging members and through the heart, and placing an elongate member through the heart along a path created by the path creating member.
According to a further aspect of the invention, a method of marking positions on the heart is provided. The method includes placing a first heart engaging member on a surface of the heart at a first position, holding the first engaging member on the heart with suction, placing a second heart engaging member on a surface of the heart at a second position opposite the first position, and holding the second engaging member on the heart with suction.
According to another aspect of the invention, a method of aligning selected positions on the heart to receive a splint assembly is provided. The method includes placing a first heart engaging member on a first surface of the heart, the first heart engaging member connected to a first handle portion, securing the first heart engaging member to the first surface of the heart, placing a second heart engaging member on a second surface of the heart, the second heart engaging member connected to a second handle portion, securing the second heart engaging member to the second surface of the heart, and moving the first handle portion relative to the first heart engaging member to connect the first and second handle portions.
According to yet another aspect of the invention, an alignment device includes a first heart engaging member having a heart engaging surface and a first receiving portion, a first arm having an end configured to releasably attach to the first receiving portion, a second heart engaging member having a heart engaging surface and a second receiving portion, a second arm having an end configured to releasably attach to the second receiving portion, and a handle assembly connected to the first and second arms.